Unfortunately, I bet if they added strain relief there would be a myriad of complaints that the cables are too hard to pack/fit in a pocket because the end is too rigid.
Personally, I've never had an issue with this, with 1st or 3rd party lightning cables, or with 1st party magsafe. But, my opinion is a lightning cable is dirt cheap, and people want them in their pocket when worried about battery, whereas a new magsafe charger is expensive and should have more robustness.
Personally, I've never had an issue with this, with 1st or 3rd party lightning cables, or with 1st party magsafe. But, my opinion is a lightning cable is dirt cheap, and people want them in their pocket when worried about battery, whereas a new magsafe charger is expensive and should have more robustness.